Halogen-Free Decorative Homogeneous Surface Coverings

Abstract

Halogen-free decorative surface covering compositions comprising a polymer blend, the polymer blend comprising: a) at least one thermoplastic elastomer, the thermoplastic elastomer being a block copolymer comprising hard and soft sequences, wherein the hard sequence is a (co)polymer of one or more vinyl aromatic monomer(s) and wherein the soft sequence is a (co)polymer of one or more alkylene(s) or of a mixture of one or more alkylene(s) and one or more vinylaromatic monomers; b) at least one thermoplastic polyurethane.

1 . A halogen-free decorative floor, wall or ceiling covering composition comprising a polymer blend, said polymer blend comprising:
 a) at least one thermoplastic elastomer, said thermoplastic elastomer being a block copolymer comprising hard and soft sequences, wherein the hard sequence is a (co)polymer of one or more vinyl aromatic monomer(s) and wherein the soft sequence is a (co)polymer of one or more alkylene(s) or of a mixture of one or more alkylene(s) and one or more vinylaromatic monomers;   b) at least one thermoplastic polyurethane.   
     
     
         2 . The halogen-free decorative floor, wall or ceiling covering composition of  claim 1  wherein the at least one thermoplastic elastomer (a) comprises between 10 and 70% by weight, preferably between 10 to 60% by weight, more preferably between 20 and 60% by weight of hard sequences. 
     
     
         3 . The halogen-free decorative floor, wall or ceiling covering composition of  claim 1  wherein the at least one thermoplastic elastomer (a) comprises from 30 to 90% by weight, preferably from 40 to 80% by weight, more preferably from 50 to 70% by weight of at least one vinyl aromatic monomer. 
     
     
         4 . The halogen-free decorative floor, wall or ceiling covering composition according to  claim 1 , wherein the at least one thermoplastic elastomer (a) is selected from the group consisting of styrene-butadiene-styrene, styrene-isoprene-styrene, styrene-isobutylene-styrene, styrene-ethylene-butylene-styrene and styrene-ethylene-propylene-styrene. 
     
     
         5 . The halogen-free decorative floor, wall or ceiling covering composition according to  claim 1  wherein the at least one thermoplastic polyurethane (b) comprises an aromatic thermoplastic polyurethane. 
     
     
         6 . The halogen-free decorative floor, wall or ceiling covering composition according to  claim 1  comprising from 25 and 70% by weight, preferably from 30 to 60% by weight, more preferably from 40 to 50% by weight of the polymer blend, said polymer blend comprising from 60 to 20% by weight, preferably from 50 to 30% by weight of thermoplastic elastomer (a) and from 40 to 80% by weight, preferably from 50 to 70% by weight of thermoplastic polyurethane (b), the sum of (a) and (b) being 100%. 
     
     
         7 . The halogen-free decorative floor, wall or ceiling covering composition according to  claim 1  comprising from 20 to 70% by weight, preferably from 30 to 60% by weight, more preferably from 40 to 50% by weight of one or more filler(s) and from 0.1 to 10% by weight, preferably from 0.2 to 8% by weight, more preferably from 0.3 to 6% by weight of the one or more pigments and/or dyes. 
     
     
         8 . The halogen-free decorative floor, wall or ceiling covering composition according to  claim 1  comprising from 0.5 to 5% by weight, preferably from 1.5 to 4.5% by weight, more preferably from 2 to 4% of one or more silicones selected from the group consisting of the siloxane homopolymers or copolymers comprising dimethylsiloxane units, methylhydrogen siloxane units, diphenylsiloxane units, phenylmethylsiloxane units, dimethylhydrogen siloxane units and trimethylsiloxane units. 
     
     
         9 . The halogen-free decorative floor, wall or ceiling covering composition according to  claim 1 , wherein said thermoplastic elastomer (a) and said thermoplastic polyurethane (b) together constitute 100% of said polymer blend. 
     
     
         10 . The halogen-free decorative floor, wall or ceiling covering composition according to  claim 6 , wherein said composition comprises between 30 and 75% by weight of one or more ingredients selected from the group consisting of lubricants, compatibilizers, silicones, antioxidants, fillers, pigments, dyes and additives, wherein the polymer blend and the one or more ingredients together constitute 100% of said composition. 
     
     
         11 . Process for the preparation of a halogen-free decorative surface covering, comprising the steps of:
 a) providing a plurality of single coloured strands by mixing and compounding the different components of each single colour composition according to  claim 1 ;   b) granulating each single coloured strand separately to form single coloured granules or merging the plurality of single coloured strands and granulating the merging outcome to form multi coloured granules;   c) converting said single or multi coloured marbled granules into a multi coloured halogen-free surface covering preferably by means of calendering or pressing.   
     
     
         12 . The process according to  claim 11  wherein the compounding step a) is performed at a temperature comprised between 140 and 220° C., preferably between 150 and 200° C., more preferably between 160 and 190° C. 
     
     
         13 . The process according to  claim 11  wherein the merging outcome of step b) is obtained from calendering or extruding the plurality of single coloured strands. 
     
     
         14 . The process according to  claim 11  wherein the calendering in step b) is performed at a temperature comprised between 110 and 160° C., preferably between 120 and 150° C., more preferably between 130 and 140° C. 
     
     
         15 . The process according to  claim 11  wherein the extruding in step b) is performed at a temperature comprised between 40 and 150° C., preferably between 80 and 150° C., more preferably between 100 and 140° C. 
     
     
         16 . The process according to  claim 11  wherein the belt press of step c) operates at:
 a temperature comprised between 130 and 220° C., preferably between 150 and 210° C., more preferably between 170 and 200° C.; 
 a speed comprised between 2 and 25 m/min, preferably between 10 and 18 m/min, more preferably between 12 and 16 m/min. 
 a pressure comprised between 3 and 20 bar, preferably between 5 and 18 bar, more preferably between 8 and 15 bar; 
 
     
     
         17 . The process according to  claim 11  wherein the calender of step c) operates at:
 a temperature comprised between 130 and 220° C., preferably between 150 and 210° C., more preferably between 170 and 200° C.; 
 a speed comprised between 2 and 25 m/min, preferably between 10 and 18 m/min, more preferably between 12 and 16 m/min. 
 
     
     
         18 . The method according to  claim 11  comprising the additional step of contacting the multi coloured halogen-free surface covering with a topcoat layer said topcoat layer comprising a cross-linked material. 
     
     
         19 . The method according to  claim 11 , wherein the topcoat layer is obtained from curing a radiation curable coating composition, said radiation curable composition comprising ethylenically unsaturated acrylic, ester, ether or urethane comprising polymers, oligomers or monomers.